Text: "Unlike X-ray C-T scans, MRIs use no ionizing radiation, but only radio waves and powerful magnetic fields to generate clear, highly detailed images of the body's interior. MRIs create images of the body by using radio waves in a strong magnetic field to energize nuclei of atoms in the body. The energized metallic hydrogen nuclei emit (reradiate) radio signals that are detected by a scanner and converted by a computer into two-dimensional images on a video screen."

See Also:

Source: 23